package com.mb.common.utils;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;

public class IPUtils {
	private static Logger logger = LoggerFactory.getLogger(IPUtils.class);

	/**
	 * 获取IP地址
	 * 
	 * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
	 * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
	 */
	public static String getIpAddr(HttpServletRequest request) {
		String ipAddress = null;
		ipAddress = request.getHeader("x-forwarded-for");
		logger.info("x-forwarded-for:" + ipAddress);
		if (ipAddress == null || ipAddress.length() == 0|| "unknown".equalsIgnoreCase(ipAddress)) {
			ipAddress = request.getHeader("Proxy-Client-IP");
			logger.info("Proxy-Client-IP:" + ipAddress);
		}
		if (ipAddress == null || ipAddress.length() == 0|| "unknown".equalsIgnoreCase(ipAddress)) {
			ipAddress = request.getHeader("WL-Proxy-Client-IP");
			logger.info("WL-Proxy-Client-IP:" + ipAddress);
		}
		if (ipAddress == null || ipAddress.length() == 0|| "unknown".equalsIgnoreCase(ipAddress)) {
			ipAddress = request.getRemoteAddr();
			if (ipAddress.equals("127.0.0.1")) {
				// 根据网卡取本机配置的IP
				InetAddress inet = null;
				try {
					inet = InetAddress.getLocalHost();
				} catch (Exception e) {
					e.printStackTrace();
				}
				ipAddress = inet.getHostAddress();
			}
		}

		// 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
		if (ipAddress != null && ipAddress.length() > 15) { // "***.***.***.***".length() == 15
			if (ipAddress.indexOf(",") > 0) {
				ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
			}
		}
		logger.info("ipAddress:" + ipAddress);
		return ipAddress;
	}

}
